how to declare byte in STM32

[MNapi]

I am using in adruino declaration

uint16_t x;

.

.

.

byte lowerByte = lowByte(x);

 byte upperByte = highByte(x);

Wire.beginTransmission(0x23); //Slave Address

 Wire.write(lowerByte);

 Wire.write(upperByte);

 Wire.endTransmission();

to send bigger numbers over I2C and it works fine

when I use byte to declare number in Keil it does not recognize it .

is there anyway to make the same in Keil ?

[Tesla DeLorean]

// overly verbose, but the compiler will optimize out

uint8_t lowerByte = (uint8_t)((x >>0) & 0xFF);

uint8_t upperByte = (uint8_t)((x >>8) & 0xFF);

[S.Ma]

check the definition of byte, lowByte() and highByte() which is not shown here.

Then you can check if there are any compiler dependent issues.